1. Field of the Invention
The invention relates to a sensor, particularly a level sensor, a pressure measuring transformer, or the like, which exhibits a housing that contains a sensor and exhibits a cable bushing that can be detached from the housing and inserted into the housing, such that the cable bushing has at least one form-seal.
2. Background Art
FIG. 1 shows a sensor 10 known to the prior art, with a housing 11 containing an electric measuring transformer 12 and a sensor 13. The sensor also exhibits a cable bushing 14 for guiding a cable 15. The cable bushing 14 may exhibit an elastomer form-fitting seal 17, or a plurality of elastomer form-fitting seals, which are compressed by a pressure screw. Coming out of the cable are leads 19, which are inserted in the electrical measuring transformer by means of plug elements 100 that may take of the form of impact connectors, flat plugs, or lead terminal sleeves. To improve the seal, the elastomer form-fitting seals 17 and 18 are often glued to the cable 15 and a cable seat 101. In the disassembly process, which can involve, e.g., a servicing event, the glued-on elastomer form-fitting seals 17 and 18 are necessarily damaged, with the result that they can no longer be used and must be replaced by new ones. When there is no adhesive connection between the cable 15 and the elastomer seals 17 and 18, said elastomer form-fitting seals 17 and 18, over the course of time, may cling so firmly, both the to cable 15 and to the cable seat 101, that the elastomer seals 17 and 18 are inevitably destroyed when the cable bushing 14 is removed. To prevent the destruction of the elastomer seals 17 and 18 during disassembly of the cable bushing 14, means 16 are frequently employed to reduce friction, but over the course of time these means are washed out by the media surrounding the sensor 10, or they decompose or evaporate at high temperatures. For this reason, it is not possible in the present art to disassemble the cable bushing 14 without destroying the elastomer form-fitting seals 17 and 18. In the course of disassembling the cable bushing 14 the plug elements 100 are necessarily removed from the electronic measuring transformer 12. Detachment of the plug elements 100 while supply voltage is being applied may result in, e.g., an undesired short-circuit due to rotating motion in the cable bushing 14.